MODEL OF A SUPERCONDUCTING PHASE-TRANSITION

A model of a superconducting phase transition is studied in terms of two competing dynamical symmetry chains. It is shown that a sharp phase transition occurs in the limit of large-dimensional representations and that, for finite representations, the smoothed-out phase transitions can be understood clearly in analytical terms. It is also shown, both numerically and analytically, that the Mottelson approximation becomes exact for large-dimensional representations. © 1990 The American Physical Society.